Trealy Farm Charcuterie is the sort of place a clever marketing man might invent. It's a bucolic Welsh longhouse in the Monmouthshire hills – there's a herd of goats in one field, a pair of enormous hairy pigs in another – and has the rural image a conglomerate might slap on its packaging to disguise the fact that they're knocking out sausages from a business park in Swindon.

At Trealy Farm Charcuterie, there's no fancy packaging. Across the farmyard from his family's kitchen, inside an old barn, is the tiny workshop where James Swift and his two butchers are turning the finest free-range, rare breed Welsh pigs into the finest free-range, rare-breed charcuterie: sausages, salamis, saucisson, prosciutto, chorizo… the list goes on. And on.

Nobody has produced charcuterie in Britain on this scale, so there were no traditional recipes, and no body of knowledge to draw on. Figuring out how to air-dry the meat in the damp Welsh hills took two years of experimentation. And a tour of Europe's finest cured meat spots. "We started off in Norcia, in Umbria," says Swift. "The grandfather at one place had been making hams all his life. And then we visited more commercial places.

"We tried to figure out how to apply what we'd seen to what we have here. And half the time we'd find out that there was no reason why they did something, it was just one of those grandmotherly things, like you have to hang the sausage at a certain angle."

Swift studied history at Cambridge and worked in London for an education quango where he met his wife Ruth. They sold up and bought the hill farm with 135 acres attached. "I was brought up on a smallholding and Ruth's family were sheep farmers in north Wales so it was in the blood."

They aren't just taking on the Mediterranean countries, they're upping the game. "On the continent they produce the best possible meat from pretty mediocre pigs," says Swift.

His pigs – when we visited, there were two from Prince Charles's Highgrove estate – are free-range rare breeds, which mature slower. "If we didn't use free-range pigs, our costs would halve."

But would they taste as good? Inside the temperature-controlled drying rooms hang rows of handmade sausages dangling from hooks. They taste overwhelmingly of proper meat, soft and melting in the mouth. But then, restaurateur Mark Hix who nominated Trealy Farm Charcuterie for our awards, says he gave Jose from Joselito, one of the best Spanish ham producers, a plate to try, "and he couldn't believe that it was produced in Britain".